The present invention relates in general to telephone testing equipment, and more specifically to a method and apparatus for remote verification of trunk operation without requiring the use of an external device.
Telephones are traditionally connected to the Public Switched Telephone Network (PSTN) through a pair of wires running from home or office to the Telephone Company Central Office (CO).
There are two basic types of analog Central Office trunks: loop start (LS) and ground start (GS), although other less common types are available. Both types of trunks use two wires that are termed Tip and Ring to provide the signaling but use different electrical signaling mechanisms to xe2x80x9cstartxe2x80x9d the line. In addition, ground start lines are polarity sensitive while loop start lines are not. Audio is transmitted over the lines in a mode using amplitude modulated differentially balanced signals. Other signaling carried by the lines includes ringing and Dual Tone Multi-Frequency (DTMF) digits dialed by the subscriber. The foregoing describes what is commonly known as Plain Old Telephone Service (POTS). For each additional telephone, another pair of wires must be used.
Digital Subscriber Loop (DSL) trunks are used to transfer data packets to home and office at rates of up to 2 Mbps. These packets may contain data, such as may be received from an Internet connection and/or multiple channels of digitized voice data. Whereas in the past a single pair of wires supported only a single voice or data connection with Customer Premises Equipment (CPE) such as a telephone or PC, the advent of DSL permits multiple virtual voice and data connections over a single DSL line. A device known as an Integrated Access Device (IAD) de-multiplexes the voice channels and converts them back to analog POTS lines, while also providing a connection for the data channels to a Local Area Network (LAN).
When telephony devices are installed, the installer must ensure that the lines are connected to the proper interface with the proper polarity. Additionally the installer must program the devices (electronically or mechanically) to indicate which line type is connected (i.e. loop start or ground start).
Traditionally, Customer Premise Equipment (CPE) devices such as telephones had no field programmable requirements. As the industry advanced, switches or jumpers were used to handle simple programming requirements. The addition of microprocessors and microcontrollers to CPE devices has created a requirement for field programming, which has generally been handled by connecting a Dual Tone Multi Frequency (DTMF) telephone to the CPE. A unique password is entered via DTMF in order to gain access to a programming mode of the CPE. In this mode, unique combinations of digits indicate certain actions to be performed. Also, values stored in internal non-volatile memory fixed locations, typically known as registers, may be accessed during normal operation to provide information on how certain actions should be performed. Unique combinations of dialed digits can also be used to trigger specific actions without entering program mode. Text based computer terminals connected to a local digital data port have also been used to gain access to the programming mode. This, in turn, has led to the deployment of remotely accessible data ports via modems connected to a POTS line. With the introduction of the Internet and the World Wide Web (WWW), it has become common for CPE devices to feature a data network connection and to provide graphical programming and data display using web pages. It is therefore desirable to provide a tool for simple programming of the CPE using any of the existing methodologies as well as text based programming using a Telnet connection or WWW access over the Internet.
According to the present invention, an IAD is provided which ensures correct connection to the CO trunk using only a minimum of tools. Once connected, the device may be remotely activated to test the trunk and communicate the results of the test to a remote location. Trunk tests may be triggered in a number of ways. They may be triggered by a power on cycle, or by a unique programmable code entered from a DTMF telephone. A text based computer terminal attached to the serial data port of the apparatus may also trigger tests. Alternatively, tests may be remotely triggered by a Web browser attached to the serial data port, by Telnet or by a Web browser connected to the World Wide Web (WWW). The results of such tests may be determined by observing integrated LEDs on the apparatus, by a locally generated message that is transmitted via an integrated modem over a POTS line or by a remote query from the Internet via Telnet or WWVV Web pages.